<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<style type="text/css">
		.a {
			width: 100px; height:100px;
			border: #2a2a2a solid 1px;
		}
		
		.a:hover {
			border: #ff0000 solid 1px;
		}
	</style>

	<div class="a">

	</div>

	<body>
	</body>

</html>